With the advent of electronic devices having a high frequency, a capacitor, an electronic component, also has been required to have a large capacitance and a superior impedance characteristic in a high frequency region. Recently, in order to reduce the impedance in this high frequency region, an electrolytic capacitor using conductive polymer having a high electrical conductivity has been commercialized.
An electrolytic capacitor includes an anode foil a dielectric film formed on a surface of the anode foil and a conductive polymer layer formed on the dielectric film. The surface of the anode foil is roughened to have pits formed therein.
The conductive polymer layer may be formed by, for example, in addition to chemical polymerization or electropolymerization, a dispersion method by which conductive polymer particles are impregnated in a capacitor element. Chemical polymerization may damage the dielectric film due to oxidizing agent. Chemical polymerization or electropolymerization can hardly form a conductive polymer layer uniformly, thus providing the conductive polymer layer with a large thickness with a large amount of conductive polymer.
Patent Literatures 1 and 2 are known as prior art publications related to the present invention.